Mimmie and Minnie are two twin sisters who are introduced in Mother; they are also the younger siblings of Ninten, the main protagonist of the game. They do both have essential roles in the beginning of the game, when a poltergeist is haunting their house. Both of the sisters get attacked by inanimate objects which during the odd circumstances are brought to life. Minnie gets attacked by a Lamp; an encounter which can be avoided by Ninten if he chooses to save Mimmie from her attacker instead. The Doll which attacks Mimmie is compulsory and vital to defeat as it acts as the first boss and also holds one of the eight melodies. After the poltergeist has disappeared, Ninten can receive an infinite supply of Orange Juice from both Mimmie and Minnie, which lasts until Ninten has obtained the Basement Key.

Later in the game, Minnie resides at the main floor of the house and will gladly take care of items which Ninten may deposit and withdraw; which can be pretty useful as Ninten can at his maximum only carry eight items (twenty-four items once he has been accompanied by his traveling partners). The Mysterious Goods-Keeper who resides in Magicant has the same functions as Minnie, as the goods keeper will be available for deposition of items, which she then will send to Ninten's house.

In EarthBound, Tracy has a similar role to Minnie and appears to be based off of her.

Trivia

During the cutscenes at the ending of the game in the English prototype which did not appear in the original Japanese release, Minnie's color scheme has changed to look identical to Mimmie's; which more specifically is that all of her red-colored aspects have changed to pink. This was fixed in the Mother 1+2 port, however.